Reduction Of Sodium Concentration Research Articles

Pre-emptive use of glucose 5% as the standard drug solvent reduces hypernatremia in critically ill patients.

Hypernatremia presents a common complication in intensive care unit (ICU) patients, associated with increased mortality and length of stay. This study investigates the effect of sodium chloride 0.9% compared with glucose 5% solution as the standard intravenous drug diluent on the prevalence of hypernatremia in a medical ICU. This is a retrospective before-and-after study comparing two consecutive patient groups before and after the standard drug solvent was changed from sodium chloride 0.9% to glucose 5% solution for compatible medications. A total of 265 adult COVID-19 patients admitted between October 2020 and March 2021 to the study ICU were included, with 161 patients in the timeframe when sodium chloride 0.9% was employed as the standard drug solvent and 104 patients when glucose 5% was used. Routine sodium measurements from arterial and venous blood gases, along with heparinized lithium plasma, were analyzed. The daily sodium concentrations and the prevalence of severe hypernatremia (>150mmol/l) were assessed during the first 8 days after ICU admission. Baseline characteristics were similar between the two groups. The cumulative volume of intravenous drug diluents was comparable. In the glucose 5% group, about half of the total drug diluent volume was glucose 5% [mean (SD): 2251.6 (2355.4) ml], compared to 135.0 (746.9) ml (P<.001) in the control group. Average sodium concentrations diverged after day two, with the glucose 5% group consistently showing lower sodium levels (mean difference of ∼2.5mmol/l). Severe hypernatremia occurred less frequently in the glucose 5% group (6.6%vs. 20%). Glucose 5% solution as the standard intravenous drug solvent significantly reduced sodium concentrations and the occurrence of severe hypernatremia. This simple modification in solvent choice may serve as a preventive strategy against hypernatremia in the ICU. Further prospective research is necessary to determine associated clinical outcomes. The trial was registered in the German Clinical Trials Register (DRKS00031877).

The Effect of Different Storage Temperatures over Time on the pH of Mammary Gland Secretions in Periparturient Mares.

The objectives of this study were (i) to determine pH and electrolyte concentrations in MGS collected prepartum and at parturition, (ii) to characterize mare milk pH during the first week postpartum, and (iii) to evaluate pre-foaling MGS pH at three storage temperatures. This study outlined two hypotheses: (i) all mares exhibit acidic pH, increased calcium, magnesium, and potassium, and reduced sodium concentrations regardless of prepartum pH and electrolytes; (ii) pre-foaling MGS pH varies with storage temperature and time in an initial value-dependent manner. Twenty-three multiparous mares were monitored daily from 320 days of gestation until parturition. Pre-foaling MGS was collected, and pH was immediately measured using a hand-held pH meter. Aliquots were preserved for further electrolyte analysis. Postpartum, samples from day -7 to 0 (day of foaling) were thawed, and electrolyte concentrations (calcium, magnesium, sodium, potassium) were determined. For the three storage temperatures, pH was measured at 0, 15, 30, 45, and 60 min after storage, and hourly for 10 h post-collection. A range of pH 8 to 6.5 was included to avoid bias towards a specific pH value. The chosen pH groups were 8 (range 7.8-8.2), 7.5 (range 7.3-7.7), 7 (6.7-7.2), and 6.5 (6.2-6.6). Overall, storage temperature affects pH (p < 0.05). In conclusion, this study demonstrated that the majority of the mares had sodium-potassium inversion and acidic pH at foaling. Milk pH is neutral up to four days after foaling, becoming slightly alkaline afterwards, with undetermined clinical significance. The pH of MGS showed minimal variation across storage temperatures, except for pH ~7.5, which increased to ~8 post-storage. This study is the first to address these physiological and practical questions about MGS pH in periparturient mares.

Endophytic fungi are able to induce tolerance to salt stress in date palm seedlings (Phoenix dactylifera L.).

Date palm, typically considered a salinity-resistant plant, grows in arid and semi-arid regions worldwide, and experiences decreased growth and yields under salt stress. This study investigates the efficacy of endophytic fungi (EF) in enhancing the salinity tolerance of date palm seedlings. In this experiment, EF were isolated from date tree roots and identified morphologically. Following molecular identification, superior strains were selected to inoculate date palm seedlings (Phoenix dactylifera L., cv. Mazafati). The seedlings were subjected to varying levels of salinity stress for 4months, utilizing a completely randomized factorial design with two factors: fungal strain type (six levels) and salinity stress (0, 100, 200, and 300mM sodium chloride). The diversity analysis of endophytic fungi in date palm trees revealed that the majority of isolates belonged to the Ascomycota family, with Fusarium and Alternaria being the most frequently isolated genera. In this research, the application of fungal endophytes resulted in increased dry weight of roots, shoots, root length, plant height, and leaf number. Additionally, EF symbiosis with date palm seedling roots led to a reduction in sodium concentration and an increase in potassium and phosphorus concentrations in aerial parts under salt-stress conditions. While salinity elevated lipid peroxidation, consequently increasing malondialdehyde (MDA) levels, EF mitigated damage from reactive oxygen species (ROS) by enhancing antioxidant enzyme activity, including superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APX), while promoting proline and total soluble sugar (TSS) accumulation. The colonization percentage generally increased with salinity stress intensity in most strains. According to the results, the application of EF can alleviate the adverse effects of salinity stress and enhance the growth of date palm seedlings under saline conditions.

Ion regulation in a freshwater crab, Potamonautes warreni: The effects of trace metal exposure.

Crustaceans inhabiting metal-contaminated freshwaters are susceptible to toxic insult to their osmoregulatory systems. The main osmoregulatory organs of decapod crustaceans, the gills, are continually bathed in freshwater and are therefore at risk from trace metal impacts. The effects of chronic (21 d) exposure to raised dissolved concentrations of Zn, Cd, Cu and Pb on aspects of hydromineral balance were investigated in Potamonautes warreni, a freshwater crab endemic to rivers in South Africa at potential risk from trace metal contamination from mining operations. Generally, hydromineral balance of P. warreni was tolerant to chronic metal exposures although sublethal cadmium exposure of 860 µg.l-1 for 21 days resulted in a reduced sodium concentration in the haemolymph. A chronic exposure to 43 µg.l-1 cadmium produced an elevated maximum unidirectional sodium uptake, possibly resulting from acclimation to the metal exposure. Branchial Na+/K+-ATPase and V-Type H+-ATPase activity were not affected by chronic in vivo Cd (43 µg.l-1) and Zn (500 µg.l-1) exposures. An important aspect of ameliorating metal toxicity may be through antioxidants and therefore the effects of applying a reducing agent were tested following in vitro metal treatment. Inhibition of Na+/K+-ATPase could be prevented by pre-incubation with a reducing agent, indicating the importance of antioxidants in reducing metal toxicity in this species. Although this study demonstrates the physiological resilience of P. warreni to dissolved trace metal impacts, the energetic consequences of long-term exposure are as yet not known.

Severe Hyponatremia and Continuous Renal Replacement Therapy: Safety and Effectiveness of Low-Sodium Dialysate

Rationale & ObjectiveIn patients with severe hyponatremia in the setting of acute kidney injury or end-stage kidney disease, continuous renal replacement therapy (CRRT) using standard-sodium (140 mEq/L) fluids may lead to excessively rapid correction of plasma sodium concentration. Use of dialysate and replacement fluids with reduced sodium concentrations can provide a controlled rate of correction of plasma sodium concentration.Study DesignWe performed a single-center retrospective analysis of the safety and effectiveness of this approach in patients with plasma sodium concentrations ≤ 126 mEq/L who underwent CRRT for 24 or more hours using low-sodium (119 or 126 mEq/L) dialysate and replacement fluids. Change in plasma sodium level was assessed at 24 and 48 hours after initiation of low-sodium CRRT and at the end of treatment.Setting & ParticipantsBetween January 2016 and June 2018, a total of 23 hyponatremic patients underwent continuous venovenous hemodiafiltration using low-sodium dialysate and replacement fluids; 4 patients were excluded from analysis because of CRRT duration less than <24 hours.ResultsThe 19 patients included in the study had a mean age of 56 years, 11 (58%) were men, and 15 (79%) were white. The initial mean plasma sodium level was 121 mEq/L and the initial CRRT effluent dose was 27 mL/kg/h. Only 2 (11%) patients had an increase in plasma sodium concentration > 6 mEq/L at 24 hours. Mean changes in plasma sodium levels at 24 and 48 hours and at the time of CRRT discontinuation were 3, 3, and 6 mEq/L, respectively. None of the patients developed osmotic demyelination syndrome.LimitationsKey limitations were small sample size and lack of a control group.ConclusionsUse of low-sodium dialysate and replacement fluids is a safe strategy for the prevention of overly rapid correction of plasma sodium levels in hyponatremic patients undergoing CRRT.

Directional hedonic thresholds for sodium concentration in hamburger

Abstract A portion of the food industry is not reducing sodium concentrations in their products due to the risk of losing the sensory acceptance of their final products. In this context, the aim of the present study was to determine the compromised acceptance threshold (CAT) and the hedonic rejection threshold (HRT) of sodium concentration in hamburger meat. Furthermore, these thresholds were also determined by targeting sensory attributes (aroma, texture, flavor, and overall impression). The reduction in sodium concentration led to a shift in the acceptances of flavor (CATf = 0.631%), aroma (CATa = 0.630%), overall impression (CAToi = 0.601%) and texture (CATt = 0,482%). This depreciation, however, did not result in sensory rejection of the hamburger aroma and texture . On the other hand, a sensory rejection started to occur for both flavor and overall impression when the sodium concentration reached values of 0.170% and 0.014%, respectively. CAT and HRT directional determinations were found to provide useful information for food industries. This indicates the acceptance and rejection of each of the aforementioned attributes that are those most affected by stimulus variation (sodium reduction). Moreover, the reported outcome should stimulate sodium reduction in foods.

Potassium Citrate is Better in Reducing Salt and Increasing Urine pH than Oral Intake of Lemonade: A Cross-Over Study.

BackgroundUrine solute supersaturation leads to the formation of urinary tract caliceal stones. Many parameters can be involved in the supersaturation of solutes in urine, such as pH. Uric acid has pKa ≤5.5, and it is solubilized at pH ≥5.5. The objective of the study was to evaluate the effects of potassium citrate and lemonade supplementation in pediatric patients with urolithiasis.Material/MethodsA total of 126 children who had lower ureteral stones calculi and fragments with severe colic pain participated in this cross-over study. Children drank lemonade (2 mEq/kg/day citrate) in 3 divided doses for 5 days. After a 15-day washout period, children drank 2 mEq/kg/day of potassium citrate in 3 divided doses for 5 days. On the sixth of the day of individual intervention, a 24-h urine sample was collected and evaluated for pH, urine volume, citrate level, uric acid level, magnesium, phosphorus, potassium, and sodium. Urinary parameters for 1-day urine collection measurements after each supplementation were compared with baseline using the Mann-Whitney test following Tukey post hoc test at 95% confidence level.ResultsPotassium citrate supplementation resulted in reduction of sodium concentration (p=0.0337; q=3.76) and increased pH of urine (p=0.0118; q=4.389). However, urine volume, citrate level, and uric acid level, as well as elemental magnesium, phosphorus, and potassium, remained unchanged after 5 days of supplementation with potassium citrate or lemonade.ConclusionsPotassium citrate supplementation is an effective therapy for preventing pediatric urolithiasis, with acceptable adverse effects.

NONOSMOTIC EFFECT OF POLYETHYLENE GLYCOL ON PERCENT SURVIVAL AND GROWTH OF RICE

Salinity is one of the major environmental factors limiting crop productivity. For this reason, two greenhouse experiments were conducted in Faculty of Agriculture, Cairo University, Egypt, during the year 2015 using two rice varieties to evaluate the effects of various levels of osmotic stress caused by polyethylene-glycol 6000 (PEG) and NaCl. Furthermore, it was tested whether the inhibitory effect of salinity on growth, sodium and chloride concentration by two different varieties was greater under NaCl or PEG treatment. The first experiment was undertaken to separate osmotic and ionic aspects of salinity damage to rice (Oryza sativa L.).Seedlings of IR28 (salt-sensitive) and Nona Bokra (salt-tolerant) rice varieties were transferred to salinized nutrient solution containing 85 mol m-3NaCl (-3.0 bars) with or without PEG 6000 (-2.0 bars, 45 gL-1). Plants were grown up to 30 days in the salinized solutions. The second experiment was designed to determine the effect of salinity (85 mol m-3NaCl) with or without PEG 6000 (-0.5 bar, 11 g L-1)on growth, uptake and transport of sodium and chloride in two rice varieties differing in salt tolerance. The results indicated that survival of salt-tolerant variety (Nona Bokra) was increased significantly by adding PEG (-2.0 bars). The addition of PEG also reduced the rate of death of rice plants compared with NaCl alone. Also, data showed that PEG 6000 (0.5 bar, 11 gL-1) reduce sodium concentration in root of IR28 and Nona Bokra but its effect upon sodium concentration in shoot of the two varieties was more pronounced than the reduction of Na+ concentration in root. Highly significant differences were obtained between zero and 11 gL-1 PEG. The result of this study is strongly indicated that addition of PEG dramatically lessened the toxicity of NaCl to rice seedlings.

The Ameliorative Effects of Silicon on Salt-Stressed Sorghum Seedlings and Its Influence on the Activities of Sucrose Synthase and PEP Carboxylase

The Ameliorative Effects of Silicon on Salt-Stressed Sorghum Seedlings and Its Influence on the Activities of Sucrose Synthase and PEP Carboxylase Under salt stress, Silicon is considered a beneficial element for the growth of higher plants as it alleviates the harmful effects caused by salt. In the present study, Sorghum bicolor L. seedlings were grown hydroponically in growth units, filled with continuously aerated half strength of Hoagland-nutrient solution. Different treatments were manipulated to examine the negative effects of NaCl and the combined effect of NaCl with Si on seedlings growth, chlorophyll content, soluble protein content, ion accumulation, phosphoenolpyruvate carboxylase (PEPCase) and sucrose synthase (SS) activities. The salt induced decrease in seedling growth was relieved upon treatment with Si. Meanwhile, the sucrose and glucose levels were significantly increased and there was a reduction in sodium concentrations in the salt-stressed plants treated with silicon. The PEPCase activity in sorghum seedlings subjected to salt-stress was higher in the treatment with Si than that without Si, but did not significantly differ from that of control.

Ameliorative effects of Ca2+ on deleterious effects of salinity on nutrients uptake and some morphological traits of two genotypes of lentil (Lens culinaris M.)

This experiment was conducted with two genotypes of lentil (MLC321 and MLC323), two levels of calcium (0 and 5 mM Ca as CaSO4) and five salinity levels (0, 4, 8, 12 and 16 dS/m) as a factorial experiment, based on completely randomized design with three replications. Seeds were sown in plastic pots and sampling of seedlings was done after 6 weeks. Results showed that in both genotypes, plant height decreased at all salinity levels (P≤ 0.05). At higher salinity levels (more than 4 dS/m), total root area and root length were decreased in both genotypes. In both genotypes, significant reduction in leaf dry weight was observed at 12 and 16 dS/m salinity levels, and root dry weight at all salinity levels (except 4 dS/m in MLC323 genotype). Salt stress increased the concentration of sodium in leaves and roots of both genotypes. Potassium and calcium concentrations of leaves increased at some salinity levels; while the concentration of these elements decreased in the roots. In MLC321 genotype, calcium treatment significantly (P≤ 0.05) increased plant height and leaf area and dry weight at 4 dS/m salinity level. In MLC323 genotype, calcium treatment significantly (P≤ 0.05) reduced sodium concentration of roots at 8 dS/m and leaf potassium at 4 dS/m salinity level. In both genotypes, calcium treatment at high levels of salinity (12 and 16 dS/m) was unable to offset the negative effects of salinity. It seems that using calcium sulfate, due to its role in osmoregulation, can limit the damages caused by low salinity (4 dS/m) in lentil.

Methane production from marine microalgae Isochrysis galbana

Methane production from marine microalgae Isochrysis galbana was assessed before and after mechanical and chemical pretreatments. Mechanical pretreatment resulted in a 61.7% increase in soluble Chemical Oxygen Demand. Different hydrolysis conditions were evaluated by varying temperature - T, sulfuric acid concentration - AC and biomass suspension concentration (measured as particulate COD - CODp) using an experimental design. The most significant interaction occurred between AC and T and the hydrolysis condition that showed the best result in the anaerobic digestion step was the condition at 40°C with addition of 0.2% (v/v) acid for 16h (9.27LCH4/kgVS). The low methane yields were attributed to inhibitory sodium concentrations for anaerobic digestion. Eliminating inhibitory sodium in the anaerobic digestion by biomass prewashing, there was a 71.5% increase in methane yield for biomass after acid hydrolysis, demonstrating the need for pretreatment and reduction in sodium concentration in the anaerobic digestion.

Relationship of hyponatremia in bronchiolitis to clinical outcomes

For many years, hyponatremia has been recognized in adult critical care as a predictor of worse outcomes. The reasons for the phenomenon are not clear but may be due to the direct effects of reduced sodium concentrations leading to abnormal fluid shifts. Some of these patients have syndrome of inappropriate anti-diuretic hormone, and others have iatrogenic fluid overload. There have been few studies in the pediatric population. In this issue of The Journal, Luu et al from the University of Colorado report a retrospective cohort study of children admitted to the pediatric intensive care unit (PICU) with bronchiolitis. Serum sodium concentrations were obtained within the first two hours of admission and correlated with clinical outcomes. Results showed that 22% of 102 children had hyponatremia within two hours of admission. These children had increased mortality, increased days on the mechanical ventilator, increased PICU length of stay, and increased need for noninvasive ventilatory support. The authors conclude that children with bronchiolitis who have a serum sodium of less than 135 mEq/L within two hours of admission to the PICU fare worse than their cohorts with normal sodium values. This conclusion begs the question: What is the mechanism, and should this be the focus of future investigations? The type and composition of fluid administered during the first 24 hours will be an important variable to study. Hyponatremia in Children with Bronchiolitis Admitted to the Pediatric Intensive Care Unit Is Associated with Worse OutcomesThe Journal of PediatricsVol. 163Issue 6PreviewTo characterize the relationship between hyponatremia (serum sodium <135 mEq/L) and clinical outcomes in children ages 1 month to 2 years admitted to the pediatric intensive care unit (PICU) with bronchiolitis. Full-Text PDF

The Impact of NaCl Substitution with KCl on Proteinase Activities Cell‐Free Extract and Cell‐Free Supernatant at Different pH Levels and Salt Concentrations: Lactobacillus delbrueckii ssp. bulgaricus and Streptococcus thermophilus

The effect of NaCl substitution with KCl at different pH levels (6.0, 5.5, and 5.0) and salt concentrations on proteinase activities of cell-free and supernatant of Lactobacillus delbrueckii ssp. bulgaricus 11824 (L. bulgaricus) and Streptococcus thermophilus MS (ST) was investigated. MRS broths were separately mixed with 4 salt treatments (NaCl only, 1NaCl:1KCl, 1NaCl:3KCl, and KCl only) at 2 different concentrations (5% and 10%) and incubated at 37 °C for 22 h. The cell pellets were used to prepare proteinase of cell-free extract and the cell-free supernatants were used as source of extracellular proteinases. The proteolytic activities and protein contents of both fractions were determined. The supernatants after incubation of both fractions with 3 milk caseins (α-, β-, κ-casein) were subjected to angiotensin-converting-enzyme inhibitory (ACE-inhibitory) activity and proteolytic activity by ortho-phthalaldehyde (OPA) method. Significant differences were observed in ACE-inhibitory activities and proteolytic (OPA) between salt treatments of cell-free extract and cell-free supernatant of L. bulgaricus and S. thermophilus at same salt concentration and same pH level. There was a significant effect of pH level and salt treatments interaction on ACE-inhibitory activity, OPA activity and azocasein activity. To reduce sodium concentration in cheese by substituting of NaCl with KCl, it was important to study the effect on starter culture proteinases which play a vital role in ripening and texture profile of cheese.

NHE Inhibition Does Not Improve Na+ or Ca2+ Overload During Reperfusion: Using Modeling to Illuminate the Mechanisms Underlying a Therapeutic Failure

Reperfusion injury results from pathologies of cardiac myocyte physiology that develop when previously ischemic myocardium experiences a restoration of normal perfusion. Events in the development of reperfusion injury begin with the restoration of a proton gradient upon reperfusion, which then allows the sodium-proton exchanger (NHE) to increase flux, removing protons from the intracellular space while importing sodium. The resulting sodium overload drives increased reverse-mode sodium-calcium exchanger (NCX) activity, creating a secondary calcium overload that has pathologic consequences. One of the attempts to reduce reperfusion-related damage, NHE inhibition, has shown little clinical benefit, and only when NHE inhibitors are given prior to reperfusion. In an effort to further understand why NHE inhibitors have been largely unsuccessful, we employed a new mathematical cardiomyocyte model that we developed for the study of ischemia and reperfusion. Using this model, we simulated 20 minutes of ischemia and 10 minutes of reperfusion, while also simulating NHE inhibition by reducing NHE flux in our model by varying amounts and at different time points. In our simulations, when NHE inhibition is applied at the onset of reperfusion, increasing the degree of inhibition increases the peak sodium and calcium concentrations, as well as reducing intracellular pH recovery. When inhibition was instituted at earlier time points, some modest improvements were seen, largely due to reduced sodium concentrations prior to reperfusion. Analysis of all sodium flux pathways suggests that the sodium-potassium pump (NaK) plays the largest role in exacerbated sodium overload during reperfusion, and that reduced NaK flux is largely the result of impaired pH recovery. While NHE inhibition does indeed reduce sodium influx through that exchanger, the resulting prolongation of intracellular acidosis paradoxically increases sodium overload, largely mediated by impaired NaK function.

In vivo magnetic resonance imaging of sodium and diffusion in rat glioma at 21.1 T

Sodium and diffusion magnetic resonance imaging (MRI) in intracranial rat 9L gliomas were evaluated over 6-8 days using the advanced sensitivity of sodium MRI at 21.1 T. Glioma doubling time was 2.4-2.6 days. Glioma sodium signal was detected using the ultra-short echo time of 0.15 ms. The high resolution 3D sodium MRI with pixels of 0.125 μL allowed for minimizing a partial volume effect often relevant to the MRI of low intensity signals. Tumor sodium and diffusion MRI were evaluated for two separate subclones of 9L cells with different resistance to 1,3-bis(2-chloroethyl)-1-nitrosurea detected by pre-surgery assays. In vivo, after implantation, resistant 9L cells created tumors with significantly reduced sodium concentrations (57 ± 3 mM) compared with nonresistant 9L cells (78 ± 3 mM). The corresponding differences in diffusion were less, but also statistically significant. During tumor progression, an increase of glioma sodium concentration was observed in both cell types with a rate of 2.4-5.8 %/day relative to normal brain. Tumor diffusion was not significantly changed at this time, indicative of no alterations in glioma cellularity. Thus, changes in sodium during tumor progression reflect increasing intracellular sodium concentration and mounting metabolic stress. These experiments also demonstrate an enhanced sensitivity of sodium MRI to reflect tumor cell resistance.

Effects of Mo back contact thickness on the properties of CIGS solar cells

AbstractEffects of Mo back contact thickness on the photovoltaic properties of CIGS solar cells were investigated. When the Mo was thin, an increase in series resistance and leakage current adversely affected the FF (fill factor) in solar cells fabricated using the Mo layers. On the other hand, when the thickness of the Mo layer was as thick as 0.8 μm, sodium out‐diffusion from the SLG decreased. The resulting reduced sodium concentration in CIGS films grown on top of the contact layers resulted in reduced open circuit voltage (VOC). As a consequence of the tradeoff between the decreased sodium diffusion for thicker Mo layers and reduced FF in thin Mo layers, the optimal Mo thickness was found to be 0.2 μm. Water vapor introduction during the deposition of the CIGS absorber layer was found to be effective in improving overall photovoltaic properties especially in solar cells with thin Mo back contacts. With water vapor introduction, cell efficiencies as high as 16.9% and 16.0% were obtained with Mo thicknesses of 0.2 μm and 0.07 μm, respectively. (© 2009 WILEY‐VCH Verlag GmbH &amp; Co. KGaA, Weinheim)

Effect of Substrate Sodium Content on Crystallization and Photocatalytic Activity of TiO2Films Prepared by DC Magnetron Sputtering

The effect of sodium content of the glass support on the crystallinity of sputteredTiO2films and photocatalytic breakdown of ethanol has been studied. It was found that the activity of the as-deposited (amorphous) films does not depend on the type of support used. The chemical composition of the glass support does influence the activity of annealed films. When using soda-lime glass support sodium diffuses into the film upon annealing, suppressing anatase crystallization and decreasing its photocatalytic activity. To decrease the influence of sodium, soda-lime glass coated with an e-beam evaporatedSiO2barrier layer was used with good result. A reduced sodium concentration in the film leads to well crystallized anatase after annealing. An increased photocatalytic activity was observed for these films.

Silicon deposition in the root reduces sodium uptake in rice (Oryza sativa L.) seedlings by reducing bypass flow

Sodium chloride reduces the growth of rice seedlings, which accumulate excessive concentrations of sodium and chloride ions in their leaves. In this paper, we describe how silicon decreases transpirational bypass flow and ion concentrations in the xylem sap in rice (Oryza sativa L.) seedlings growing under NaCl stress. Salt (50 mM NaCl) reduced the growth of shoots and roots: adding silicate (3 mM) to the saline culture solution improved the growth of the shoots, but not roots. The improvement of shoot growth in the presence of silicate was correlated with reduced sodium concentration in the shoot. The net transport rate of Na from the root to shoot (expressed per unit of root mass) was also decreased by added silicate. There was, however, no effect of silicate on the net transport of potassium. Furthermore, in salt-stressed plants, silicate did not decrease the transpiration, and even increased it in seedlings pre-treated with silicate for 7 d prior to salt treatment, indicating that the reduction of sodium uptake by silicate was not simply through a reduction in volume flow from root to shoot. Experiments using trisodium-8-hydroxy-1,3,6-pyrenetrisulphonic acid (PTS), an apoplastic tracer, showed that silicate dramatically decreased transpirational bypass flow in rice (from about 4.2 to 0.8%), while the apparent sodium concentration in the xylem, which was estimated indirectly from the flux data, decreased from 6.2 to 2.8 mM. Direct measurements of the concentration of sodium in xylem sap sampled using Philaenus spumarius confirmed that the apparent reduction was not a consequence of sodium recycling. X-ray microanalysis showed that silicon was deposited in the outer part of the root and in the endodermis, being more obvious in the latter than in the former. The results suggest that silicon deposition in the exodermis and endodermis reduced sodium uptake in rice (Oryza sativa L.) seedlings under NaCl stress through a reduction in apoplastic transport across the root.

Metabolic Complications during Regional Citrate Anticoagulation in Continuous Venovenous Hemodialysis: Single-Center Experience

Background: Regional anticoagulation with trisodium citrate is an effective form of anticoagulation for continuous renal replacement therapy (CRRT) in patients at a high risk of bleeding. In a prospective, observational study we compared an established regional citrate anticoagulation protocol [Mehta R et al: Kidney Int 1990;38:976–981] versus a standard heparin anticoagulation protocol focusing on acid-base and electrolyte derangements as well as on cost effectiveness. Methods and Results: 209 patients were included in the study. In 37 patients, citrate was used as the sole anticoagulant, 87 patients received low-dose heparin plus citrate, and 85 patients received only heparin as anticoagulant. A customized dialysate solution was used for citrate-anticoagulated CRRT (no buffer, no calcium, reduced sodium concentration). Filter life was significantly higher during citrate anticoagulation compared to heparin anticoagulation (80.2 ± 60 vs. 30.2 ± 32 h; p < 0.001). No difference was found between citrate and citrate-heparin anticoagulation (p = 0.310). Metabolic alkalosis was observed in more than 50% of patients on citrate anticoagulation. Alkalosis developed within the first 72 h after initiating treatment and could be reversed in almost all cases by increasing the dialysate flow rate. Hypercalcemia was observed in 13 patients on citrate anticoagulation. Patients with impaired liver function were particularly at risk. Systemic hypocalcemia, hypernatremia, and anion gap acidosis were not observed. Citrate anticoagulation was well tolerated hemodynamically. A longer filter life during citrate anticoagulation translated into a significant cost reduction compared to standard heparin anticoagulation (p < 0.01). Conclusion: Regional anticoagulation with trisodium citrate in combination with a customized calcium-free dialysate is a safe and effective alternative to a heparin-based anticoagulation regimen.

Actin cytoskeleton, tubular sodium and the renal synthesis of dopamine

The present study has examined the effect of colchicine and cytochalasin B, two cytoskeleton disrupter compounds, on the formation of dopamine in slices of rat renal cortex loaded with exogenous L-3,4-dihydroxyphenylalanine (L-DOPA); the deamination of newly formed dopamine into 3,4-dihydroxyphenylacetic acid (DOPAC) was also examined. The accumulation of newly formed dopamine and DOPAC in kidney slices loaded with L-DOPA (10-100 microM) was found to be dependent on the concentration of L-DOPA, being similar in control conditions and in preparations treated with increasing concentrations of colchicine (5, 10 and 50 microM). By contrast, cytochalasin B (5, 10 and 50 microM) was found to produce a concentration-dependent reduction in the formation of dopamine and of its deaminated metabolite DOPAC in kidney slices loaded with L-DOPA (10-100 microM). The inhibitory effect of cytochalasin B on the formation of dopamine was found to be completely abolished in kidney slices pretreated with ouabain (500 microM) or when sodium concentration in the incubation was reduced from 120 to 20 mM. On its own, ouabain (500 microM) was found to reduce the formation of dopamine by 55%; the effect of reducing sodium concentration in the incubation medium to 20 mM was also a significant reduction (53% decrease) in the formation of dopamine. The accumulation of DOPAC did always parallel that of its parent amine. It is concluded that the renal formation of dopamine is dependent on the concentration of sodium in the medium and the integrity of the tubular transport of sodium, namely on the association between actin cytoskeleton and Na+,K(+)-ATPase, appears to be determinant.